Catheter having plurality of stiffening members

ABSTRACT

The invention includes a catheter having an elongate main body having a proximal section and a distal section. The elongate main body further includes a plurality of stiffening members disposed along the length of the elongate main body. The plurality of stiffening members includes a first stiffening member and a second stiffening member. The catheter can also include a balloon formed from a tubular member having a recess defined in a portion of its surface. A tapered or thinned balloon is formed from a process by which material is removed from a tubular member prior to formation of the balloon.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication Ser. No. 60/684,135, filed May 23, 2005 and is acontinuation-in-part of U.S. patent application Ser. No. 11/136,640,filed May 23, 2005, which claims the benefit of U.S. Provisional PatentApplication Ser. Nos. 60/575,643 filed on May 27, 2004, and 60/654,022filed on Feb. 17, 2005, the entire contents of each are incorporatedherein by reference.

BACKGROUND OF INVENTION

1. Field of Invention

The present invention relates to a catheter for treating a luminalsystem of a patient. Particularly, the present invention is directed toa catheter having a plurality of stiffening members to vary thestiffness along the length of the catheter body.

2. Description of Related Art

A variety of catheter devices are known in the art for treating theluminal system of a patient. Of such devices, many are directed totreating the cardiovascular system of a patient. One such cardiovascularsystem treatment includes percutaneous transluminal coronary angioplasty(PTCA); a procedure for treating heart disease. This procedure generallyentails introducing a catheter assembly into the cardiovascular systemof a patient via the brachial or femoral artery, and advancing thecatheter assembly through the coronary vasculature until a balloonportion thereon is positioned across an occlusive lesion. Once inposition across the lesion, the balloon is inflated to a predeterminedsize to radially compress against the atherosclerotic plaque of thelesion to remodel the vessel wall. Subsequently, the balloon is deflatedto allow the catheter assembly to be withdrawn from the vasculature.

Often the site of the occlusive lesion is only reached by a tortuouspathway through the vasculature of the patient. The difficulty inaccessing such regions requires that a successful catheter must be quiteflexible to follow the tortuous path into the tissue, and at the sametime, stiff enough to allow the distal end of the catheter to bemanipulated from an external access site.

To address this problem, catheters having varied flexibility along theirlength have been developed. For example, each of U.S. Pat. No. 4,782,834to Maguire and U.S. Pat. No. 5,370,655 to Burns discloses a catheterhaving sections along its length which are formed from materials havinga different stiffness; U.S. Pat. No. 4,976,690 to Solar discloses acatheter having an intermediate waist portion which provides increasedflexibility along the catheter shaft; U.S. Pat. No. 5,423,754 toCornelius discloses a catheter having a greater flexibility at itsdistal portion due to both a material and dimensional transition in theshaft; and U.S. Pat. No. 5,649,909 to Cornelius discloses a catheterhaving a proximal portion with greater stiffness due to the applicationof a polymeric coating thereto.

Such conventional methods and systems generally have been consideredsatisfactory for their intended purpose. However, catheters still sufferfrom certain performance issues, such as by lack of pushability and kinkresistance. Although solutions to this problem have been developed asdiscussed supra, there still remains a continued need in the art for acatheter having varied flexibility to enhance pushability, kinkresistance and versatility. The present invention provides a solutionfor these problems.

SUMMARY OF THE INVENTION

The purpose and advantages of the present invention will be set forth inand apparent from the description that follows, as well as will belearned by practice of the invention. Additional advantages of theinvention will be realized and attained by the methods and systemsparticularly pointed out in the written description and claims hereof,as well as from the appended drawings.

To achieve these and other advantages and in accordance with the purposeof the invention, as embodied herein and broadly described, theinvention includes a catheter having an elongate main body having aproximal end and a distal end. The elongate main body has at least aproximal section and a distal section. The elongate main body furtherincludes a plurality of stiffening members disposed along a length ofthe elongate main body. The plurality of stiffening members includes afirst stiffening member and a second stiffening member, each stiffeningmember having a proximal end and a distal end. The first stiffeningmember is disposed in an overlapping spaced relationship relative to thesecond stiffening member. Optionally, the elongate main body can furtherinclude additional stiffening members disposed along a length of theelongate main body with each additional stiffening member being disposedin an overlapping spaced relationship relative to another stiffeningmember.

In further accordance with the invention, at least one stiffening membercan be secured to the catheter in a variety of ways. For example and notlimitation, the at least one stiffening member can be secured to anadapter, e.g., luer, hub, manifold, or a reinforcement or fillermaterial, or support member. Alternatively, the at least one stiffeningmember can be secured to the elongate main body by way of an engagementmember. In this manner, an engagement member can be secured to thesurface of the elongate main body such that a space or cavity is definedfor engaging the at least one stiffening member.

In accordance with a further aspect of the invention, the catheterincludes a plurality of stiffening members configured to control or varyaxial flexibility along a length of the elongate main body. Theplurality of stiffening members can include a first stiffening memberand a second stiffening member, each stiffening member having adifferent flexibility. For example and not limitation, the secondstiffening member can be configured to have a greater flexibility thanthe first stiffening member to define a catheter having greaterflexibility distally along its length. Alternatively, the firststiffening member can be configured to have a greater flexibility thanthe second stiffening member to define a catheter having a greaterstiffness distally along its length, if desired. Further, the pluralityof stiffening members can include a third stiffening member having aflexibility different than at least one of the first and secondstiffening members.

The plurality of stiffening members can be configured to control or varythe flexibility along the elongate main body in a variety of ways. Forexample, a first stiffening member and a second stiffening member caneach be formed from a material having a different flexibility. In thisregard, each of the plurality of stiffening members can be formed from avariety of materials including but not limited to metal, metal alloy,polymer, composite, carbon, and reinforced materials. Notably, thestiffening member can be in the form of a wire, strand, rod, tubularmember, filament and the like.

As yet another alternative, the flexibility or bending stiffness of thecatheter or a portion of the catheter can be varied depending on theorientation of the stiffening member and the catheter portion. Forexample, if the stiffening member is oriented such that it is centrallylocated within a lumen of a tubular member, the stiffness of the tubularmember would be relatively uniform across the length of the tubularmember when the tubular member is in a bending orientation. However, ifthe stiffening member is attached or secured to the inner wall of thetubular member, the tubular member would have a variation in stiffnessalong its length depending on the direction the catheter is bent.

At least one of the plurality of stiffening members can include areduced cross-sectional area or an increased cross sectional area alongits length, if desired. In this manner, any of the stiffening memberscan be configured to include a distal taper, a proximal taper, orinclude a taper at its distal and proximal ends.

Alternatively, at least one of the plurality of stiffening members caninclude at least one cut or a plurality of cuts defined along itslength. The at least one cut or plurality of cuts can be, for example, acircumferential cut or a longitudinal cut along the length of thestiffening member. Each of the plurality of circumferential cuts alongthe length of the stiffening member define at least one circumferentialgroove which are spaced along the length of the stiffening member. Thespacing between adjacent grooves can be varied along the length of thestiffening member to define a stiffening member having a variedflexibility along its length, if desired. Alternatively, the spacingbetween adjacent grooves can be substantially similar along the lengthof the stiffening member.

The plurality of longitudinal cuts along a length of the stiffeningmember can include at least a first longitudinal cut and a secondlongitudinal cut having a different length.

Moreover, the plurality of stiffening members can have a variety ofconfigurations, such as linear configurations and non-linearconfigurations. In this regard, the non-linear configuration can includea wavy configuration and a helical configuration. Moreover, at least onestiffening member can include a linear configured portion and anon-linear configured portion along its length.

At least one stiffening member can be disposed circumferentially aboutthe outer surface of the tubular member to define at least one cluster,which includes a plurality of helical turns or rotations having a pitchand circumferentially disposed about a section of the tubular memberalong a length of the cluster. The helical turns associated with anindividual cluster are configured to have a predetermined pitch. Thepitch can be varied or constant along the length of the cluster. Forexample, the varied pitch can include helical turns having an increasingpitch along the length of the cluster or a decreasing pitch along thelength of the cluster. Further, the helical turns can include a constantpitch along the length of the catheter.

The at least one cluster may include a plurality of clusters along thelength of the tubular member configured to control or vary axialflexibility along a length of the tubular member. The plurality ofclusters can include a first cluster including a first plurality ofhelical turns and a second cluster including a second plurality ofhelical turns, each cluster having a different flexibility. For exampleand not limitation, the second cluster can be configured to have agreater flexibility than the first cluster to define a tubular memberhaving greater flexibility along its length. Alternatively, the firstcluster can be configured to have a greater flexibility than the secondcluster to define a catheter having greater stiffness along its length,if desired.

The plurality of clusters can be configured to control or vary theflexibility along the tubular member in a variety of ways. For example,a first cluster including a first plurality of helical turns can beconfigured to have a first pitch and a second cluster including a secondplurality of helical turns can be configured to have a second pitch. Thefirst cluster can be associated with a first section of the tubularmember and the second cluster can be associated with a second section ofthe tubular member. In this regard, the first and second plurality ofhelical turns can each be configured to include a pitch that is constantalong the length of the first cluster and second cluster, respectively.The first plurality of helical turns can be configured to have a longerpitch than the pitch of the second plurality of helical turns. In thismanner, the first section of the tubular member is configured to have agreater flexibility than the second section of the tubular member due tothe orientation of the first and second clusters relative to the tubularmember, and the configuration of the first and second plurality ofhelical turns and their respective first and second pitches along thelength of the corresponding cluster. The first cluster can be disposedat the distal section of the tubular member and the second cluster canbe disposed at a proximal section of the tubular member to define atubular member having an increased flexibility along its distal length.Alternatively, the first cluster can be disposed at a proximal sectionof the tubular member and the second cluster can be disposed at a distalsection of the tubular member to define a tubular member having anincreasing stiffness along its distal length.

Alternatively, the plurality of clusters can each be formed from amaterial having a different flexibility to control and vary theflexibility along the tubular member. For example, a first clusterincluding a first plurality of helical turns and a second cluster havinga second plurality of helical turns can each be formed from a materialhaving a different flexibility.

In accordance with the invention, the plurality of clusters can comprisemultiple elements joined by interconnectors. The interconnectors can belinear or non-linear members. Alternatively, the at least one stiffeningmember can be a single element helically disposed along the length ofthe tubular member configured to include at least one cluster.

Further, the cluster including helical turns can be formed from avariety of materials including but not limited to metal, metal alloy,polymeric material, composite material, carbon, fiber reinforcedmaterials. The cluster including helical turns can be in the form of awire, strand, rod, filament, tubular member and the like.

In accordance with a further aspect of the invention, the tubular membercan include a coating applied to the outer surface of the tubularmember. In this regard, the coating can be a topcoat to overlie the atleast one stiffening member so as to provide a tubular member having asmooth outer surface, a base layer directly contacting the outer surfaceof the tubular member or the coating can include multiple coatings toprovide a topcoat and a base layer.

In accordance with a further aspect of the invention, a catheter isprovided which comprises an elongate main body including at least aproximal section and a distal section, each of the proximal section andthe distal section of the elongate main body having a lumen definedtherethrough. The catheter further includes a guidewire tube defining aguidewire lumen extending through at least a portion of the distalsection of the elongate main body. The proximal section includes ahypotube and the distal section includes an inflatable member. Aplurality of stiffening members is disposed along a length of theelongate main body.

In accordance with a further aspect of the invention, the catheter canfurther include at least one reinforcement member to reinforce a sectionof the elongate main body. The at least one reinforcement member can bedisposed adjacent to or near at least one guidewire port disposed acrossthe elongate main body. In one embodiment, the reinforcement member canbe added to the elongate main body to reinforce the elongated main bodyat a welding area. Alternatively, the at least one reinforcement membercan be disposed between two components along the elongate main body at awelding region to secure the components of the elongated main body andtightly seal the welding region. The reinforcement member can provideadded material to the wall of the elongate main body and help to avoidthinning of the wall of the elongate main body during welding or otherprocesses. Avoidance of wall thinning of the elongate main bodytherefore provides a tight seal, even when high pressure is applied inthe lumen of the elongate main body. Accordingly, in one embodiment, thereinforcement member is a sealing member to seal a section of theelongate main body. The reinforcing member can be, for example, atubular member or filler material.

The plurality of stiffening members includes a first stiffening memberand a second stiffening member. The first stiffening member can bedisposed in an overlapping and spaced relationship with the secondstiffening member. Alternatively, the second stiffening member can bedisposed distal of the first stiffening member such that a gap isdefined between the stiffening members. If desired, a support member canbe disposed between the first and second stiffening members.

In accordance with one aspect of the invention, the distal end of atleast one of the plurality of stiffening members has a length extendingwithin the inflatable member. The guidewire tube can extend within theinflatable member and the catheter can further include at least onemarker band disposed circumferentially around an outer surface of theguidewire tube. At least a portion of at least one of the plurality ofstiffening members can be disposed between the outer surface of theguidewire tube and an inner surface of the at least one marker band. Theat least one of the plurality of stiffening members an be slidinglyreceived between the outer surface of the guidewire tube and the innersurface of the marker band.

The at least one of the plurality of stiffening members can furtherinclude a protrusion disposed along its length. The protrusion can bedisposed proximate the distal end of the stiffening member and provide abutting engagement with the marker band.

In yet another aspect of the invention, a process is provided in which aballoon having a tapered profile is achieved. The process includesproviding a tubular member formed of a material having an outer surface,a proximal region, a distal region, and an intermediate regiontherebetween. A recess is defined at a predetermined targeted site onthe outer surface of the tubular member. The recess is formed byremoving a predetermined amount of material from the target site. Thetarget site is predetermined to correspond to a portion of a balloon,formed from the tubular member, at which a tapered profile is desired.For example, the predetermined target site can correspond to theconical, waist, or working portions of the balloon. Accordingly, aballoon having a cone portion, waist portion, and/or working portionhaving a tapered profile can be configured from the tubular member. Inone preferred embodiment, the material is removed by laser ablation.

In a further aspect of the invention, a sheath is provided for a ballooncatheter. In one embodiment, the sheath is configured to be utilizedwith a rapid exchange type balloon catheter. The sheath includes aproximal sheath section and a distal sheath section. The proximal sheathsection is stationary and is configured to overlie a proximal portion ofthe rapid exchange catheter. In this regard, the stationary sheathsection covers at least the proximal port disposed in the sidewall ofthe catheter body. Preferably, the proximal sheath section includes anopening along its length that corresponds in location with the proximalport disposed in the sidewall of the catheter body so as to provideaccessibility to the proximal port. The distal sheath section isretractable and overlies at least the balloon portion of the catheter.In operation, the distal sheath section is retracted by actuation of anactuator such as a pull-wire or other mechanism. During retraction, thedistal sheath section slides proximally toward the stationary sheathsection to expose the balloon. For example, the distal sheath sectioncan be configured to telescopically slide over a surface of the proximalsheath section. Alternatively, the distal sheath section can be acompressible bellow member. In operation, the distal sheath has a lengththat compresses proximally to expose the balloon portion of catheter.

The sheath can further include an intermediate sheath section disposedbetween proximal and distal sheath sections. In this manner, theintermediate sheath section is a bellowed sheath section operativelyconnected to the proximal and distal sheath sections. In operation, thebellowed sheath is proximally compressed and proximally displaces thedistal sheath section to expose the balloon section of the catheter.

In further accordance with the invention, an actuator can be a pull wirethat is operatively attached to the distal sheath section or theintermediate sheath section. The pull wire can be disposed in at least aportion of the catheter shaft. For example and not limitation, the pullwire can be disposed in the proximal portion of the inflation lumen ofthe catheter. In this manner, a distal section of the pull wire exitsthe catheter body at an intermediate section of the catheter body andextends distally exteriorly along the outer surface of the catheterbody. In this regard, the proximal sheath section covers the portion ofthe pull wire that is disposed exterior to the catheter body. Theportion of the pull wire that is disposed in the lumen of the cathetershaft can be disposed in a dedicated lumen or can be secured to theinner surface of the lumen of the catheter.

It is to be understood that both the foregoing general description andthe following detailed description are exemplary and are intended toprovide further explanation of the invention claimed.

The accompanying drawings, which are incorporated in and constitute partof this specification, are included to illustrate and provide a furtherunderstanding of the method and system of the invention. Together withthe description, the drawings serve to explain the principles of theinvention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a first representative embodiment of acatheter having an elongate main body including a proximal section, adistal section, and a plurality of stiffening members in accordance withthe present invention;

FIG. 2 is a schematic view of another representative embodiment of acatheter having an elongate main body including a proximal section, adistal section and a plurality of stiffening members in accordance withthe present invention;

FIG. 3 is a cross sectional view at line 3-3 of the catheter of FIG. 1in accordance with an embodiment of the present invention;

FIG. 4A is a cross sectional view at line 4-4 of the catheter of FIG. 1in accordance with an embodiment of the present invention;

FIG. 4B is an alternate cross sectional view at line 4-4 of the catheterof FIG. 1 in accordance with an embodiment of the present invention;

FIG. 4C is another cross sectional view at line 4-4 of the catheter ofFIG. 1 in accordance with an embodiment of the present invention;

FIG. 5 is a cross sectional view at line 5-5 of the catheter of FIG. 1in accordance with the present invention;

FIG. 6 is a cross sectional view at line 6-6 of the catheter of FIG. 1in accordance with the present invention;

FIG. 7 is a cross-sectional view at line 7-7 of the catheter of FIG. 1in accordance with the present invention;

FIG. 8 is a side view of the catheter of FIG. 1 including a guidewiredisposed in a first guidewire tube;

FIG. 9 is a side view of the catheter of FIG. 9 including the guidewiredisposed in each of first and second guidewire tubes in accordance withthe invention;

FIG. 10 is a schematic side view of another representative embodiment ofa catheter in accordance with the present invention;

FIG. 11 is a cross sectional view at line 11-11 of the catheter of FIG.10 in accordance with the present invention;

FIG. 12 is a cross sectional view at line 12-12 of the catheter of FIG.10 in accordance with the present invention;

FIG. 13 is a cross sectional view at line 13-13 of the catheter of FIG.10 in accordance with the present invention;

FIG. 14A to 14G is a schematic representation of a method to manufacturethe catheter of FIG. 10 in accordance with the present invention;

FIG. 15 is a schematic side view of another embodiment of a catheter inaccordance with the present invention;

FIG. 16 is a schematic representation of the embodiment of FIG. 15 inaccordance with the present invention;

FIG. 17A to FIG. 17 G is a schematic representation of a method tomanufacture the catheter of FIG. 15 in accordance with the presentinvention;

FIG. 18A is a schematic side view of a representative embodiment of acatheter having a plurality of stiffening members;

FIG. 18B is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members;

FIG. 18C is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members in accordance with thepresent invention;

FIG. 18D is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members in accordance with thepresent invention;

FIG. 18E is a schematic side view of a first stiffening member and asecond stiffening member, each having a taper in accordance with thepresent invention;

FIG. 18F is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members in accordance with thepresent invention;

FIG. 18G is a is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members in accordance with thepresent invention;

FIG. 18H is a schematic side view of a stiffening member secured to theelongate main body of a catheter in accordance with the invention;

FIG. 18I is a schematic side view of an alternative embodiment of acatheter having a plurality of stiffening members in accordance with thepresent invention.

FIG. 19A is a schematic side view of a stiffening member having aplurality of cuts and a reduced cross sectional area along the lengththereof in accordance with the present invention;

FIG. 19B is a schematic side view of a stiffening member having aplurality of cuts along a length thereof in accordance with the presentinvention;

FIG. 20 is a schematic side view of a catheter having a plurality ofstiffening members disposed in an overlapping and spaced relationship inaccordance with the present invention;

FIG. 21 is a schematic side view of a catheter having at least onestiffening member secured to the elongate main body in accordance withthe present invention;

FIG. 22 is a schematic side view of a catheter having a plurality ofstiffening members in accordance with the invention;

FIG. 23 is a schematic side view of a catheter having first and secondstiffening members disposed in an overlapping and spaced relation inaccordance with the invention;

FIG. 24 is a schematic side view of a catheter having a tubular memberdisposed between a plurality of stiffening members in accordance withthe invention;

FIG. 25 is a schematic perspective view of a stiffening member having atleast one longitudinal cut along a length thereof;

FIG. 26 is a schematic perspective view of a stiffening member having aplurality of longitudinal cuts, each cut having a different length,along a length of the stiffening member;

FIGS. 27A to 27 AJ is a depiction of schematic views of a plurality ofstiffening members in accordance with the present invention;

FIG. 28 depicts a stiffening member in accordance with the invention;

FIG. 29 depicts a catheter including at least one stiffening member anda support member in accordance with the invention;

FIGS. 30A and 30B each schematically depict a tubular member having atleast one stiffening member circumferentially disposed about the tubularmember in accordance with the invention;

FIGS. 31A and 31B each schematically depict a tubular member having atleast one stiffening member circumferentially disposed about the tubularmember and a coating thereon in accordance with the invention;

FIG. 32A schematically depicts a tubular member having a recess definedby a quantity of removed material from the tubular member;

FIG. 32B schematically depicts an inflatable member formed from thetubular member of FIG. 32A;

FIG. 33 is schematically depicts a tubular member of a catheter havingan actuator secured in the lumen of the tubular member in accordancewith the invention;

FIG. 34 schematically depicts a tubular member of a catheter having alumen configured to receive an actuator in accordance with theinvention;

FIGS. 35A and 35B schematically depict an embodiment of a sheath inaccordance with the invention;

FIGS. 36A and 36B schematically depict another embodiment of a sheath inaccordance with the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

Reference will now be made in detail to the present preferredembodiments of the invention, an example of which is illustrated in theaccompanying drawings. The method and corresponding steps of theinvention will be described in conjunction with the detailed descriptionof the system.

The devices and methods presented herein may be used for treating theluminal systems of a patient. The present invention is particularlysuited for treatment of the cardiovascular system and the peripheralsystem of a patient. The treatment of the cardiovascular system includesthe performance of angioplasty or delivery of balloon-expandable orself-expanding interventional devices (e.g., stents, filters, coils).The treatment of the peripheral system includes treatment of thecarotid, popliteal and renal vessels. Accordingly, the present inventionis also suitable for special endovascular vessels.

In accordance with the invention, a catheter is provided having anelongate main body. Generally, the elongate main body has at least aproximal section and a distal section. The catheter further includes aplurality of stiffening members including a first stiffening member anda second stiffening member. The first stiffening member is disposed inan overlapping and spaced relationship relative to the second stiffeningmember.

For purpose of explanation and illustration, and not limitation, anexemplary embodiment of the catheter in accordance with the invention isshown in FIG. 1 and is designated generally by reference character 100.Additional features, aspects and embodiments of a catheter in accordancewith the invention are provided in FIGS. 2 to 36 as will be described.

For purposes of illustration and not limitation, as embodied herein andas depicted in FIG. 1, catheter 100 has a main body portion including aproximal section 102, a distal section 106, and an intermediate section104 disposed between the proximal and distal sections. Each sectionhaving a proximal end and a distal end.

Generally, the proximal section of the catheter 100 includes adapter 110secured to proximal tubular member 20. Proximal tubular member 20 has abody including an outer surface, proximal end region 20 a, distal endregion 20 b and inflation lumen 20 c therebetween. Proximal end region20 a of proximal tubular member 20 is secured to adapter 110 by suitablestructure or method. For example and not limitation, proximal tubularmember can be affixed to adapter 110 by fusion, welding, overmolding,e.g., injection molding, or adhesive. Additionally, and as schematicallydepicted in FIG. 1, adapter 110 can have a distal end 110 b inoverlapping relation with a portion of proximal tubular member 20.Adapter 110 can be a hub or a handle, a manifold, or can be a luerfitting for connection with an inflation/deflation device, such as asyringe (not shown).

Proximal tubular member 20 can be made of any suitable material, such asmetal, metal alloy, carbon, carbon reinforced materials, metalreinforced polymers, boron fiber reinforced materials, glass reinforcedmaterials, aramid fiber reinforced materials, ceramic, composite,Kevlar, or polymer as described further below. The method of joining theadapter 110 and proximal tubular member 20 will depend on the materialsused. Preferably, proximal tubular member 20 further includes lumen 20 cextending therethrough in fluid communication with adapter 110.

If desired, catheter 100 can include a strain relief (not shown), whichextends from adapter 110 and is disposed along at least a portion ofproximal tubular member 20 to provide increased resistance to kinkingbetween the adapter and the proximal tubular member. The strain reliefis preferably formed of a polymeric material and extends distally alongat least a length of proximal tubular member 20. The strain relief canbe formed as a separate sleeve, or overmolded onto the proximal tubularmember 20. A variety of materials can be used for the strain reliefincluding polymers such as but not limited to FEP, PTFE, polyamide, andPEEK, and metals such as but not limited to stainless steel, andnitinol, e.g., spring.

The method or structure for joining proximal tubular member 20 tointermediate tubular member 22 will depend upon the materials used. Forexample, adhesive, welding, fusion, RF bonding, or other bondingtechniques can be employed. Particularly, if the proximal tubular memberis formed from metal and the adjacent tubular member is formed from apolymeric material, the polymeric tubular member can be joined to themetallic tubular member by utilization of a compression tool such as butnot limited to a jaw press.

In one preferred embodiment, proximal tubular member 20 is a hypotubemade of metal, such as stainless steel, and intermediate tubular memberis a polymer, such as nylon. In this embodiment, distal region 20 bincludes an outer surface having a bonding region defined by a roughenedouter surface across a length of the proximal tubular member (notshown). The roughened outer surface can be prepared by for example gritblasting or knurling a portion of the outer surface known techniques.Preferably the bonding region has a length of at least approximately 10to 20 mm to facilitate securing an adjacent tubular member to proximaltubular member 20. The bonding region can be provided at the distal endof the proximal tubular member 20 or, if desired, can be spaced proximalfrom the distal end. In further accordance with this embodiment,proximal region 22 a of intermediate tubular member 22 can be configuredto overlap at least a portion of the bonding region disposed on theouter surface of proximal tubular member 20. For example, and notlimitation, intermediate member can overlap the entire length of thebonding region defined by the roughened surface or a portion thereof.

Distal region 20 b is secured to an adjacent tubular member, such asintermediate tubular member 22, as depicted in FIGS. 1 and 2, bysuitable structure or method. As shown schematically in FIG. 1, proximalend region 22 a of intermediate tubular member 22 can be configured toform a lap joint such that proximal end region 22 a includes a proximalend that overlaps at least a portion of the distal end region 20 b ofproximal tubular member 20.

Similarly, it is not required that the bond securing proximal tubularmember to intermediate tubular member have a length equivalent to thelength of the roughened surface. For the purpose of illustration and notlimitation, the proximal region of intermediate member can be configuredto overlap an entire length of the roughened surface, for example 10 cm,but have a bonding length of only about 1 cm in the proximal portion ofthe bonding region length. Accordingly, the intermediate tubular member22 can be configured to bond to only a portion of the bonding regionthat is proximate a distal end the bonding region. Alternatively, theproximal end of intermediate tubular member 22 can be configured to forma butt joint with the distal end of proximal tubular member 20, ifdesired. In this manner, a polymeric sleeve can be disposed over thejunction defined by the butt joint to assist securing the proximaltubular member 20 to the intermediate tubular member 22, if necessary.

A variety of bonding techniques may be utilized to secure intermediatetubular member 22 to the bonding region of proximal tubular member 20.For example, and not limitation, fusion bonding, adhesive, welding, andthe like can be used.

A variety of materials can be used for proximal tubular member 20.Proximal tubular member 20 is preferably formed at least in part of asuitable metallic material, such as a metallic hypotube. For example,and not limitation, various metals can be used including stainlesssteel, nitinol, and other metal alloys. If stainless steel is used,preferably austenitic stainless steel is used. The metal or metal alloyis preferably MRI compatible, such as but not limited to niobium,tantalum, tungsten, or any variety of other paramagnetic metals.

Alternatively, the proximal tubular member 20 can be formed at least inpart of a nonmetallic material. For example and not limitation, theproximal tubular member 20 can be made of a carbon material, polymericmaterial, Kevlar, and reinforced materials such as carbon fiberreinforced material, glass fiber reinforced material, boron fiberreinforced material or liquid crystal reinforced material.

As noted above, the proximal tubular member 20 can be formed of asuitable polymeric material, such as PEEK or other relatively stiffpolymeric material. Alternatively, proximal tubular member 20 can beformed of a composite member or formed member comprising a fabricationof different polymers or materials. For example, the composite membercan be formed of an extrusion or pultrusion of different polymers, ifdesired. In this regard, a variety of methods for forming amulti-material or multi-layer tubular member can be utilized. For thepurpose of illustration and not limitation, the proximal tubular membercan be a braided polymeric member, e.g., a polymeric tube having a metalmember embedded or secured to the polymer.

Alternatively, the composite member can be formed by a dip moldingprocess, in which a mandrel is dipped into a polymer material, which isdissolved in suitable solvent, dried, and then re-dipped into anotherpolymer material to form a multi-layered polymeric composite or formedmember. As yet another alternative, the composite member or formedmember can be formed by applying a second polymeric tube about a firstpolymeric tube, applying a shrink tubing about first and secondpolymeric tube assembly and heating the assembly to fuse the first andsecond tubular members to each other. For each process for forming thecomposite or formed member described above, the outer surface of theinner polymeric tube can be roughened by mechanical or chemical means toimprove the bond between the inner and outer tubular members. Forexample, the outer surface can be roughened by mechanical meansincluding grinding, sandblasting, or Laser-ablation, or chemical meansincluding etching and leaching.

The composite member or formed member can also include a polymerictubular member loaded with particles of a different polymer. For exampleand not limitation, a PEEK or polyimide tubular member can be loadedwith PTFE particles. In this manner, the PTFE particles can beelectrostatically charged such that an electrostatic force bonds thePTFE particles to the PEEK or polyimide tubular member. A polymericouter layer, such as nylon tube, can be applied to the PTFE loadedtubular member to form a multi-material, multi-layer composite tubularmember.

The use of such materials having sufficiently high compressive strengthfor proximal tubular member 20 is particularly advantageous to enhancepushability and provide kink resistance for rapid-exchange applications.If desired, the proximal tubular member 20 can further include alubricious coating, such as a polytetrafluoroethylene or an HDPEcoating. Alternative lubricious materials can be used, however, as knownin the art. The proximal tube can also be coated with a hydrophilic or ahydrophobic coating to reduce friction, for example and not limitation,the hydrophobic coating can be silicone coating or the like, and thehydrophilic coating can be a polyvinylpyrrolidone or polyacrylamidecoating.

Generally, the proximal tubular member 20 can have a length of about 100to about 115 cm. For example and not limitation, the proximal tubularmember can be configured to have an outer diameter approximately 0.70 mmand an internal diameter of about 0.52 mm. However, as known in the art,the length and dimensions of the proximal tubular member can be varieddepending on the size and location of the lumen(s) to be traversed bythe catheter 100. For example, the proximal tubular member can beconfigured to have smaller dimensions, e.g., outer diameter and internaldiameter, if the catheter is used to treat vessels in the brain of apatient.

Intermediate tubular member includes a distal end region 22 b, andpreferably further includes lumen 22 c defined between distal end region22 b and proximal end region 22 a. As previously mentioned, proximal endregion 22 a is secured to at least a portion of proximal tubular member20, preferably at a bonding region defined by a roughened outer surface.Lumen 22 c is thus in fluid communication with lumen 20 c.

A variety of materials can be used for intermediate tubular member 22.For example, intermediate tubular member 22 can be made from anysuitable polymer material such as polyamide, PEEK, PEBAX®, PTFE, PVDF,polyimide, polyethylene, polyester, polyurethane, or liquid crystalpolymers of various suitable densities. As a further exemplaryalternative, intermediate tubular member 22 can be a composite member orformed member comprising a fabrication of several different materials.For example and as described above in detail, the composite or formedmember can be made by extrusion or pultrusion of different polymers, ifdesired. Alternatively, the composite member can be formed by dipmolding, applying a first polymeric tubing within a second tubularmember and fusing the assembly, or by a loading the polymer tubularmember with particles of a different polymer, e.g., PEEK or polyimidetubular member loaded with PTFE particles, as described above. As yetanother alternative, the intermediate tubular member can be formed froma fiber-reinforced material, such as fiber-reinforced resin material,e.g., carbon, glass, aramid, boron, or a liquid crystal reinforcedmaterial.

The dimensions of the intermediate tubular member 22 will depend uponthe intended application. For example, for a cardiovascular catheter,the intermediate tubular member 22 can have a length of at leastapproximately 10 cm, although a greater length can be used toaccommodate an overlap joint with the proximal tubular member 20. Forexample, and not limitation, the intermediate tubular member can have anouter diameter of approximately 0.85 mm and an inner diameter ofapproximately 0.70 mm. However, as will be recognized in the art, theintermediate tubular member 22 can be configured with alternate lengthsand dimensions, if desired.

In further accordance the invention, and as demonstrated in FIGS. 1 and2, catheter 100 can further include a distal tubular member 24. Distaltubular member 24 has a proximal end region 24 a, a distal end region 24b, and lumen 24 c therebetween, and extends distally from intermediatetubular member 22 to distal section 106. The distal shaft lumen 24 c isin fluid communication with lumen 22 c of intermediate tubular member22. Accordingly, an inflation lumen can be defined across a substantiallength of catheter 100. If both are provided, intermediate tubularmember 22 and distal tubular member 24 together thus define theintermediate section 104 of the catheter 100.

As shown in each of FIGS. 1, 8, and 9, a proximal end region 24 a ofdistal tubular member 24 can be secured to at least a portion of distalregion 22 b of intermediate tubular member 22, as well as to at least aportion of a guidewire tube 30.

A variety of materials and dimensions can be used for distal tubularmember 24. Indeed, if both an intermediate tubular member and a distaltubular member are provided, the two members can be formed of the samematerial and substantially the same cross section dimensions for uniformstiffness and flexibility, or even formed together as a single piece.Alternatively, the distal tubular member 24 can be formed of a differentmaterial and/or dimensions to vary flexibility along the length of thecatheter. For example, distal tubular member 24 can be made from anysuitable polymer material such as polyamide, PEEK, PTFE, PVDF, PEBAX®,polyimide, polyester, polyurethane, liquid crystal polymer, orpolyethylene of various suitable densities. As a further exemplaryalternative, distal tubular member 24 can be a composite member orformed member comprising a fabrication of several different materials,such as a coextrusion or pultrusion of different polymers.Alternatively, the composite or formed member can be made by the dipmolding process, polymer loading process, or by fusing first and secondtubular members to each other, as described in detail above.Alternatively, the distal tubular member can be a fiber-reinforcedmaterial such as fiber-reinforced resin material, e.g., carbon, glass,aramid, or boron, or liquid crystal reinforced material.

The dimensions of distal tubular member 24 will depend upon the intendedapplication. For example, for a cardiovascular catheter, the distaltubular member 24 can have a length of approximately 10 to 30 cm, andpreferably has a length of approximately 21 to 23 cm. For example, andnot limitation, the distal tubular member can have an outer diameter ofat least approximately 0.80 mm and an inner diameter of at leastapproximately 0.68 mm. However, as will be recognized in the art, thedistal tubular member 24 can be configured with alternate lengths anddimensions, if desired.

In an alternate construction, catheter 100 can have proximal tubularmember 20 extend distally from adapter 110 directly to distal tubularmember 24. By way of further example, distal tubular member 24 ofcatheter 100 can be attached directly to the proximal tubular member 20without an intervening intermediate section 22, such that distal tubularmember 24 has a proximal region secured to the bonding region ofproximal tubular member 20. In this manner, the proximal region 24 a ofdistal tubular member 24 can be in an overlapping configuration with thedistal region 20 b of proximal tubular member 20 to define anoverlapping region. Preferably, the overlapping region has a length ofapproximately 10 cm. Such a device can further improve pushability ofcatheter 100 and prevent kinking.

In accordance with another aspect of the invention, the elongate mainbody of the catheter 100 can include a feature for performing adiagnostic, an interventional, or a therapeutic procedure or treatment.Preferably, although not necessarily, such a feature is disposed atleast partially at the distal section 106 of the catheter 100. Forexample, and for purposes of illustration and not limitation, asembodied herein and as depicted in FIG. 1, the elongate main body canfurther include an inflatable member 114 disposed along a length of thecatheter 100. The inflatable member has a proximal end 114 a, a distalend 114 b, and an inflation chamber 114 c bounded by a surface ofinflatable member 114. Inflatable member 114 can be made from a varietyof materials. For purpose of illustration and not limitation, inflatablemember 114 can be made from a polyether block amide (“PEBA” ),polyamide, polyurethane, PET, PE, PTFE, polyester, composite materials,or a variety of other materials, including blends. Alternatively, theinflatable member can be made from a polyhydroxyalkanoate including butnot limited to poly-4-hydroxybutyrate, available from Tepha Inc.,Cambridge, Mass.

Inflatable member 114 can be formed from a variety of methods. Inaccordance with one aspect of the invention, a coneless inflatablemember is provided. In this manner, the inflatable member is formed froma thin walled tubular member having a proximal end and a distal end. Thethin walled tubular member is placed about the distal body portion. Eachof the proximal and distal ends of the thin walled tubular member iscompressed onto the outer diameter of the distal body portion. In thismanner, an Iris lens, a suture, a metal (with or without a non-stickcoating)band, wire, and the like can be utilized to wrap around each ofthe proximal and distal ends of the thin tubular member and compress theproximal and distal ends onto the distal body portion.

Optionally, the thin walled tubular member can be folded before thecompression step described above. For example and not limitation, thethin walled tubular member can include 2 to 10 folds. The proximal anddistal ends of the thin walled tubular member can be secured to thedistal tubular member 24 of the catheter by a variety of suitablebonding techniques, such as adhesive, fusion, or preferably by welding.including but not limited to mechanical welding, laser welding,ultrasound welding, friction welding, heat welding, including lightenergy, RF energy, or any other suitable method known in the art. Thus,if inflatable member 114 is made of nylon, it is advantageous for distalbody portion 24 to be made of a material compatible for a welded orfusion bond therebetween. For the purpose of illustration and notlimitation, the inflatable member can be welded to the distal bodyportion using light energy, adhesive, or heat welding.

In accordance with a further aspect of the invention, an inflatablemember having a tapered profile is provided. The tapered profile isachieved by a process during which a recess is defined at a targetedsite of a tubular member prior to formation of the balloon therefrom. Inthis regard, a material removing device removes a predetermined quantityof material to define the recess. The balloon having a tapered profileis formed from the tubular member. The balloon having a tapered profilehas benefits such as enhanced performance during advancement andretraction of the catheter in the vasculature of a patient, as well asenhanced maneuverability.

As schematically depicted in FIG. 32A and embodied herein, at least onerecess 116 a is defined by the removal of a predetermined amount ofmaterial from a targeted site of a tubular member 114 a. The at leastone recess 116 a has a length, depth, and pitch. The targeted site onthe tubular member can be predetermined to correspond to any portion ofthe balloon formed from the tubular member. For example and notlimitation, the targeted site can be disposed at a proximal, distal, orcentral portion of the tubular member 114 a. Further, the targeted sitecan correspond to at least one portion of the balloon including the coneportions, waist portions, and or working portion 117 of the balloon, ifdesired. In this manner, the predetermined site and/or the length, depthand pitch of the recess 116 a to be defined can be varied such that thetarget site and the configuration of the recess 116 a corresponds to thecone portion 116, waist portion 118 or alternatively or in combinationof the balloon 114 formed from tubular member 114 a, as depicted inFIGS. 32A and 32B.

As shown and depicted in FIG. 32A, first and second recesses 116 acorrespond to the proximal cone portion and the distal cone portion,respectively. In this regard, the target sites for the first and secondrecesses 116 a defined in tubular member 114 a, which correspond to theproximal and distal cone portions 116 of balloon 114 are mathematicallydeterminable by basic principles of trigonometry, as would beappreciated by one skilled in the art. For example and not limitation,to determine the target site of the tubular member, a template can beused to apply demarcations on a starting tube. The starting tube canthen be processed to form a balloon. The position of certain portions ofthe balloon, e.g., cone portion, skirt portion and/or working portion,is determined relative to the demarcations. The demarcations thatcorrespond to the portion of the tube at which a tapered or thinnedprofile is desired provides a benchmark for tubular member 114 a. Thisprocedure can be used to determine the target site for balloons ofvarious sizes, as would be appreciated in the art. Thus, the target siteof the tubular member 114 a which corresponds to the portion of aballoon to be tapered or thinned can be predetermined. In this regard,material can be removed from the targeted site to form the recess 116 aprior to forming the inflatable member 114. Accordingly, balloon havinga tapered profile is provided. One advantage of removing material fromthe tubular member as opposed to removing material after the balloon isformed is that waste material is minimized. Furthermore, removingmaterial from the balloon after it is formed often leads to unwantedchanges in polymer morphology, for example stiffer cone sections due tothe crystallinity of the polymer, and alterations in the orientation ofthe polymer chains. As the degree of crystallinity of the polymerincreases, the material increases in stiffness and brittleness. Suchchanges in the polymer morphology are undesirable and lead to a higherprofile and reduced burst pressure. Thus, it is advantageous to providea process in which material is removed from the tubular member prior toformation of the balloon. In this manner, crystallite formation isbroken down during the heating and drawing of the tubular member to formthe balloon 114 thus providing a more uniform and flexible material.

In one preferred embodiment, the material is removed from the tubularmember 114 a by laser ablation techniques, micro-machining techniques,or a combination of such techniques. Advantageously, laser ablationtechniques and micro machining techniques have high tolerance, qualityand reproducibility over other removal processes known in the art. Forthe purpose of illustration and not limitation, a source laser such asan Eximer or “Excited Dimmer” type laser could be used. However, it willbe apparent to those skilled in the art that other techniques ofmaterial removal could additionally or alternatively be employed suchas, but not limited, to precision grinding techniques, cuttingtechniques, and the like.

Further, it will be appreciated by one skilled in the art that thelength, depth and pitch of the recess 116 a defined by the removedmaterial from the tubular member can be varied to provide desired wallthicknesses at any portion of the tubular member and resultantinflatable member 114, as well as desired performance characteristics ofthe inflatable member formed from the tubular member.

In accordance with a further aspect of the invention, catheter caninclude a first guidewire lumen defined along a length of the catheterand a second lumen defined proximal to the first guidewire lumen along alength of elongate main body of catheter.

For example, and with reference to FIG. 1, catheter 100 is provided witha first guidewire tube 32 having a first guidewire lumen definedtherethrough. The first guidewire lumen 32 c accordingly can be providedwith a proximal guidewire port 32 a and a distal guidewire port 32 b influid communication therewith. Similarly, the catheter 100 is providedwith a second guidewire tube 30 having a second guidewire lumen definedtherethrough. The second guidewire lumen 30 c accordingly can beprovided with a proximal guidewire port 30 a and a distal guidewire port30 b in fluid communication therewith.

As embodied herein, the first guidewire lumen 32 c is disposed along thedistal section 106 of the catheter. For example, if an inflatable member114 is provided, first guidewire lumen 32 c extends through theinflatable member with the distal guidewire port 32 b located distal theinflatable member and the proximal guidewire lumen located proximal theinflatable member. In a preferred embodiment, inflatable member 114 ispositioned on the elongate main body of catheter 100 equidistant betweenthe proximal guidewire port 32 a and distal guidewire port 32 b, or thedistal end of the tip 70, if provided. However, inflatable member 114can also be placed closer to one port or the other, if desired.

Furthermore, and as embodied herein, the second guidewire lumen 30 c isdisposed proximal to and spaced from first guidewire lumen 32 c. Thatis, distal guidewire port 30 b of second guidewire lumen 30 c is spacedproximal from proximal guidewire port 32 a of first guidewire lumen 32c. A guidewire inserted proximally distal guidewire port 32 b thereforewill exit the catheter at proximal port 32 a. As illustrated in FIG. 1,proximal guidewire port 32 a of first guidewire lumen 32 c is preferablyaxially aligned with distal guidewire port 30 b of second guidewirelumen 30 c. Advantageously, and as embodied herein and depicted in FIGS.8 and 9, this arrangement provides an operator with an option to feedguide wire 60 solely through lumen 32 c of first guidewire tube 32, asmentioned above and schematically shown in FIG. 8, or alternatively,feed guidewire 60 through each of first guidewire lumen 32 c and secondguidewire lumen 30 c of second guidewire tube 30, as shown in FIG. 9.

In a preferred embodiment of the invention, at least the first guidewirelumen 30 c is defined by a first guidewire tube 30. The first guidewiretube 30 embodied herein, is joined at its distal end region to thedistal end of inflatable member 114 by conventional bonding techniquesas depicted in FIG. 1. To anchor the proximal end region of firstguidewire tube 32, and in accordance with another aspect of theinvention, a circumferential slit is formed in the wall of distaltubular member 24. The wall on the proximal side of the circumferentialslit is urged inward, such that the proximal end region 32 a of firstguidewire tube 32 extends through the slit with the wall of the distaltubular member substantially surrounding the first guidewire tube 32 asdepicted in FIG. 6. A reinforcement filler or tube can be providedproximate the slit to anchor and strengthen the joint between thetubular members.

The second guidewire lumen can be formed or defined by a separatetubular member disposed along a length of distal tubular member 24, orcan be defined by the distal tubular member 24, itself, as describedfurther below. If formed of a separate tubular member, the secondguidewire tube can be anchored at its distal end region to distaltubular member 24 in a manner similar to that of the proximal end regionof the first guidewire tube.

Particularly, and as depicted in FIG. 1 in accordance with either aspectof the invention, distal tubular member 24 further includes gap 24 dalong its length. Gap 24 d is in fluid communication with the exteriorof catheter 100. For purpose of illustration and not limitation, gap 24d can be constructed by placing two circumferential slits through thewall of distal tubular member 24 to define a flap region. The flapregion is depressed toward lumen 24 c of distal tubular member 24. Asbest viewed from FIG. 6, which illustrates a cross section of a portionof catheter 100 at gap 24 d, the depressed flap portion is depressedwithin lumen 24 c such that a portion of the wall of distal tubularmember 24 has a concave shape. Further, and as schematically shown inFIG. 1, the depressed flap region of distal tubular member 24 isdisposed between a first guidewire tube 32 and a second guidewire tube30. As schematically shown in FIG. 1, second guidewire tube 30 isdisposed proximal to gap 24 d and first guidewire tube 32 is disposeddistal to gap 24 d. Advantageously, gap 24 d allows fluid communicationbetween the exterior of catheter 100 and both the distal guidewire port30 b of second guidewire lumen 30 c, and the proximal guidewire port 32a of first guidewire lumen 32 c. Further, and as schematically depictedin FIG. 8, gap 24 d provides an exit for a guidewire 60 disposed in thefirst guidewire lumen 32 c, if desired.

As previously stated, a filler material or reinforcement tube 28 can beplaced below the gap 24 d to strengthen the region proximate the joints.If provided, a mandrel can be inserted during fusion of the members toensure an inflation lumen is maintained. Additionally, if a stiffeningelement is provided in the lumen of the tubular member, the fillermaterial provides added material to the sidewall of the tubular memberso that the stiffening member does not disrupt the sidewall of thetubular member when the catheter is manipulated during use or duringassembly.

The proximal end region of the second guidewire tube, if provided as aseparate member, can be secured or anchored in a variety of differentmanners. For example, and as embodied herein, the proximal end region ofsecond guidewire tube 30 can be secured between the distal end region 22b of intermediate tubular member 22 and the proximal end region 24 a ofdistal tubular member 24 as depicted in FIG. 1. In a preferredembodiment, the distal end region 22 b of intermediate tubular member22, as depicted in FIG. 1, can further include a longitudinal recesssuch that at least a portion of second guidewire tube 30 is nestedwithin the longitudinal recess of the intermediate tubular member 22.For the purpose of illustration and not limitation, the longitudinalrecess can be formed by necking down a distal region of the intermediatetubular member 22 or forming a dimple in of the intermediate tubularmember.

With the second guidewire tube 30 positioned between the overlappinginterface of the intermediate tubular member 22 and the distal tubularmember 24, the structure can be fused together to form a jointtherebetween. If desired, a filler material or reinforcement tube 26 canbe disposed proximate the joint as depicted in FIG. 1. Preferably, amandrel is located temporarily across the joint when the structure isfused together to define an inflation lumen 22 therethrough, as depictedin FIG. 3.

Alternate constructions for the second guidewire lumen, and thecorresponding region, are describe further below.

The material of construction and dimensions for the guidewire lumenswill depend upon the intended application. For example, for acardiovascular catheter, each of the first and second guidewire lumenscan be constructed from any suitable polymer such as nylon, PEEK, HDPE,polyimide, PTFE, or PTFE loaded polymer, e.g., polyimide, polyurethane,polyester, liquid crystal polymer, and the like, including blends orcomposites thereof. Further, each of the lumens can be made of one ormore extruded or pultruded materials, including multilayeredcoextrusions or pultrusions, or monolayered material, as discussedbelow. The guidewire lumens can also be made from a dip molding processor applying a first polymeric tubing within a second tubular member andfusing the assembly together.

The first guidewire lumen can have a length of at least approximately 1cm, and second guidewire lumen can have a length of at leastapproximately 17 cm.

Catheter 100 can be configured to have proximal guidewire port 30 aapproximately 10 to 30 cm, and preferably about 20 to 30 cm, proximal todistal tip 70 of catheter 100. Accordingly, catheter 100 can beconfigured such that guidewire 60 can be disposed through firstguidewire tube 32 and exits catheter body at guidewire port 32 a offirst guidewire tube 32 and then reenters catheter body 100 at distalport 30 b of second guidewire tube 30. Guidewire 60 extends proximallythrough second guidewire lumen 32 c to proximal port 30 a.

Alternatively, guidewire 60 can be disposed through guidewire tube 32and exit catheter 100 through proximal guidewire port 32 a at gap 24 d.Proximal guidewire port 32 a is preferably disposed near the proximalend 114 a of inflatable member 114. For example and not limitation,proximal port 32 a can be disposed approximately 8 cm proximal to distaltip 70. Alternatively, the proximal port 32 a can be disposed at avariety of other distances from distal tip 70, depending upon the lengthof the inflatable member 114 or the intended application. In onepreferred embodiment, the length between inflatable member 114 andproximal guidewire port 32 a is substantially the same as the distancebetween inflatable member 114 and distal guidewire port 32 b.

Generally, first guidewire tube 32 is shorter in length than secondguidewire tube 30. For example and not limitation, first guidewire tube32 can have a length of at least approximately 3 to 4 cm; althoughgenerally is dependent at least on the length of inflatable member 114.Second guidewire tube generally has a length of approximately 10 to 30cm, and preferably about 21 to 23 cm, depending on the length of theinflatable member 114. Preferably, the outer diameter of first andsecond guidewire tubes, 32 and 30, respectively, are approximately 0.55mm, and the inner diameter of first and second guidewire tubes, 32 and30, respectively, are approximately 0.42 mm. However, it should berecognized that each of first guidewire tube 32 and second guidewiretube 30 can have any suitable length and dimension, as desired.

A variety of materials can be used to form first guidewire tube 32 andsecond guidewire tube 30. For example and not limitation, either firstguidewire tube 32 or second guidewire tube 30 can be formed of suitablepolymer material such as polyamide, PEEK, HDPE, PEBAX®, PTFE, PVDF,polyimide, polyethylene, polyester, polyurethane, or liquid crystalpolymers of various suitable densities, including blends thereof.

As a further exemplary alternative, either guidewire tube 30, 32 can beformed of a composite member or formed member comprising a fabricationof several different materials. For example and as described above indetail, the composite or formed member can be made by extrusion orpultrusion of different polymers, if desired. Alternatively, thecomposite member can be formed by dip molding, applying a firstpolymeric tubing within a second tubular member and fusing the assembly,or by a loading the polymer tubular member with particles of a differentpolymer, e.g., PEEK or polyimide tubular member loaded with PTFEparticles, as described above. Alternatively, either guidewire tube canbe formed from a fiber-reinforced composite material such asfiber-reinforced resin material including but not limited to carbonreinforced material, glass reinforced material and boron reinforcedmaterial, or a liquid crystal reinforced material.

In one preferred embodiment, second guidewire tube 30 is formed of amulti-layered coextrusion, and first guidewire tube 32 is formed of amonolayer polymeric material. For example and not limitation, secondguidewire tube 30 can be formed of at least a two-layer materialincluding an inner polymeric layer and an outer polymeric layer.Preferably, the inner layer is a lubricious material and facilitatesgliding of guidewire 60 through guidewire lumen. Alternatively, theinner material can have a lubricous coating, for example, with asilicone coating.

In one preferred embodiment, the second guidewire tube is formed of aninner layer including HDPE and an outer layer including a polyamide,such as nylon. However, alternative materials can be used for either theinner layer or the outer layer as known in the art. For example, theinner layer can alternatively be formed from materials such aspolyimide, PTFE, or PTFE loaded polyimide and the outer layer can beformed from materials including nylon, nylon copolymers includingPebax®, Hytrel®, polyolefin, polyurethane, and blends thereof.Alternatively, other suitable materials can be used as known in the art.

The inner layer can be secured to the outer layer by various suitablemethods and structures, which depend on the particular selection of theinner layer material and the outer layer material, as known in the art.For example, the inner layer can be secured to the outer layer by amechanical bond, chemical bond, or other bonding means such asmechanical friction fit. For example and not limitation, a lubriciousinner layer of HDPE is mechanically bonded to an outer layer of nylon.

As mentioned above, guidewire tube 32 is preferably formed of amonolayer polymeric material. As depicted in FIG. 1, distal end ofinflatable member 114 is secured to first guidewire tube 32.Accordingly, the particular material selected for the first guidewiretube 32 should be compatible with the material selected for theinflatable member 114. Preferably, first guidewire tube 32 is formed ofa monolayer of nylon, and inflatable member 114 is a nylon balloon, suchthat a fusion bond can be formed therebetween. Alternatively, theinflatable member can be adhesively bonded to the first guidewire tube.Alternatively, both members can be formed of a PEBA material.Furthermore, the first guidewire tube can be formed of a multi-layertubular member, if desired.

In further accordance with the invention, distal tip 70 can be securedto first guidewire tube 32. As depicted, distal tip 70 is in anoverlapping configuration with the distal end of first guidewire tube32. In one embodiment, distal tip is configured to abut the distal endof inflatable member 114. Alternatively, however, distal tip 70 can beconfigured to overlap the distal end of inflatable member 114.Preferably, distal tip 70 is secured to the distal end of firstguidewire tube by heat welding. However, other methods can be used suchas using adhesives, or the like.

A variety of materials can be used to form distal tip 70. Preferably,distal tip 70 is formed of a material having a durometer less than thedurometer of the distal tubular member 24. For example and notlimitation, distal tip 70 can be formed of polyamides, including nylon,polyether block amide, high density polyethylene, polyurethane,polyesters, including HYTREL®. The particular selection of the materialfor the distal tip 70, however, is depending on the desired applicationof catheter 100.

As previously noted, the second guidewire lumen can be formed by asecond guidewire tube or by other construction. For example, FIG. 1depicts a catheter with second guidewire lumen 30 c defined by secondguidewire tube 30. The proximal guidewire port 30 a is defined wholly bythe proximal end region of second guidewire tube 30 due to the jointconfiguration previously described. In this manner, and by using atubular member with a lubricious inner layer, placement of the catheterrelative to the guidewire can be enhanced.

Between the proximal guidewire port 30 a and the distal guidewire port30 b, the second guidewire lumen 30 c can be disposed either in acoaxial relation or a side-by-side relation with the inflation lumen 24c, or even a hybrid of the two. For the purpose of illustration and notlimitation, FIG. 4A depicts a cross section of a portion of catheter 100in which second guidewire tube 30 is disposed generally coaxially withindistal tubular member 24, such that inflation lumen 24 c annularlysurrounds guidewire tube 30 and guidewire lumen 30 c.

Alternatively, as embodied herein, and as depicted in FIG. 4B, catheter100 can include a modified, dual lumen configuration. That is, secondguidewire tube 30 can be secured by any suitable bonding technique alongall or a portion of its length to a longitudinal inner surface of distaltubular member 24. Accordingly, inflation lumen 24 c surrounds only aportion of guidewire tube 30. In one preferred aspect of the invention,a light absorption welding technique of EP 1435252, the contents ofwhich are incorporated herein by reference herein, can be used.

In yet another alternative, as embodied herein and as depicted in FIG.4C, catheter 100 can be configured to include a conventional dual lumenconfiguration along at least a portion of the intermediate region 104.The term “conventional dual lumen configuration” refers to aconfiguration in which guidewire lumen 30 c′ and inflation lumen 24 care arranged generally in parallel and side-by-side relationship. Suchdual lumen configurations are available as a single extrusion ofsuitable polymer material, such as nylon or the like. If desired, and asillustrated in FIG. 4C, second guidewire tube can further include atleast a portion 30′ formed of a lubricious tube or liner, such as HDPE,PTFE, PEEK or the like. As depicted in FIG. 4C, inflation lumen 24 c canbe configured to have a crescent or generally semi-circular shapedcross-section. Such a semi-circular shaped cross section is advantageousbecause it maximizes the cross sectional area of inflation passage 24 c,thus minimizing flow resistance to inflate inflatable member 114.

Alternatively, the dual lumen member can be constructed by dip molding,shrink fitting, melting or fusing two or more tubular members together.For example, and not limitation, the second guidewire tube and aninflation tube can each be formed by a suitable liner. The guidewiretube liner and the inflation tube liner are arranged generally in aparallel and side-by-side relationship within a polymeric tubularmember. The assembly is then heated to a temperature to cause thepolymeric tubular member to melt around a substantial portion of each ofthe second guidewire tube liner and the inflation tube liner to securethe liners in a dual lumen configuration. A removable shrink wrap can beused to shape the outer surface of the member during the fusion process.

If the distal tubular member 24 is formed at least in part by a duallumen extrusion or pultrusion formed member, as described above, then anumber of different joint configurations can be used in accordance withthe invention. For example, and as embodied herein and depicted in FIG.10, the distal end region 22 b of intermediate tubular member 22 can beprovided in an overlapping configuration with the proximal end region 24a of distal tubular member 24. At least a portion of distal tubularmember includes a guidewire lumen 30 c and an inflation lumen 24 c in aside-by-side configuration.

To be received within the distal end region of intermediate tubularmember 22, at least the proximal end region of the dual lumen member canbe collapsed, as depicted in FIGS. 14A through 14G, and in particularFIG. 14C, described further below. Alternatively, the distal end regionof intermediate tubular member 22 can be received within the proximalend region of the dual lumen member, as depicted in FIGS. 17A to 17G,and particularly in FIG. 17E.

Distal tubular member 24 further includes at least one first fillermaterial or reinforcement member 26 within the inflation lumen 24 cproximate the joint between the intermediate and distal members. A crosssectional view of catheter 100 at line 11-11 of FIG. 10, as depicted inFIG. 11, demonstrates that second stiffening member 42, as describedfurther below, can be embedded in material of reinforcement member 26after fusion to form a joint therebetween. As depicted in the crosssectional view of catheter 100 in FIG. 12, the dual lumen membertransitions distally to define a portion of the catheter 100 thatincludes guidewire lumen 30 c and inflation lumen 24 c. To strengthenthe joint, filler material or a reinforcement tube is provided, and aremovable mandrel is disposed prior to fusion such that inflation lumen24 c having a circular or crescent-shaped cross section is formed, asdemonstrated in FIG. 12. Ultimately, the dual lumen member transitionsto a conventional configuration with guidewire lumen 30 c and inflationlumen 24 c in a side-by-side relationship with inflation lumen 24 chaving a crescent or substantially semi-circular cross section, asdemonstrated in FIG. 13.

For the purpose of illustration and not limitation, the catheter 100 ofFIG. 10 can be manufactured by the steps schematically and sequentiallydepicted in FIGS. 14A to 14G.

As demonstrated in FIGS. 14A and 14B, a partial circumferential cut 118is made in a dual lumen member 24 to define proximal guidewire port 30a. A series of removable mandrels 120 are used to maintain the lumensand port of the dual lumen structure, as desired, during the heating andfusion steps, as depicted in the Figures. For the purpose ofillustration, a removable mandrel 120 can be inserted into the definedproximal guidewire port 30 a and along guidewire lumen 30 c. Anotherremovable mandrel 120 can be inserted into the inflation lumen, asdepicted in FIG. 14C. The proximal region of the dual lumen member 24can be collapsed to configure the opening of proximal guidewire port 30a, as depicted in FIG. 14C. A removable shrink tubing 124 can be appliedto the dual lumen member 24. The assembly can be heated to form proximalguidewire port 30 a and to connect the collapsed proximal end of duallumen member 24 to the guidewire lumen sidewall, as depicted in FIGS.14D.

As previously described, and as shown in FIGS. 14C and 14F, areinforcement member 26 can be inserted along the elongate main body tosecure the stiffening member within the lumen of the elongate main body.Additionally, a mandrel is provided along the elongate main body todefine at least a portion of the inflation lumen through thereinforcement member 26.

As depicted in FIGS. 14E and 14F, the intermediate tubular member 22 canbe secured to the proximal end of the dual lumen tubular member byapplying a removable shrink tube 124 and appropriate application of heatto fuse the members together. FIG. 14G depicts the catheter 100including formed proximal guidewire port and joint configuration.

Alternatively, as demonstrated in FIG. 16 and FIGS. 17A to 17G, and inparticular FIG. 17E, the distal end region 22 b of intermediate tubularmember 22 having reduced cross dimension can be received and securedwithin proximal end region 24 a of distal tubular member 24. Toaccomplish this configuration, and in accordance with the another aspectof the invention, the assembly depicted in FIG. 15 can be manufacturedby the steps schematically and sequentially depicted in FIGS. 17A to17G. Particularly, and in lieu of or in addition to disposingreinforcement members 26 within the lumen at the joint, the assembly, asdepicted in FIG. 15, includes at least one first reinforcement member 26placed about at least one of distal tubular member 24 or intermediatetubular member 22 as viewed in FIG. 16 and FIG. 17F. As illustrated, thedistal member and the intermediate member can be secured by applying aremovable heat shrink tube 124 and appropriate heat to fuse the memberstogether. FIG. 17G depicts the catheter 100 including the alternativeformed proximal guidewire port and joint configuration with mandrel 120removed.

Although reference has been made to alternative methods andconfigurations for joining the proximal end of the dual lumen member tothe intermediate tube, such methods and configurations also can be usedfor joining the distal end of the dual lumen member to an adjacenttubular member as desired. For example, the distal end of the dual lumenmember can be attached to the first guidewire lumen and either an outerdistal tube member or directly to the balloon using the methods similarto that of FIGS. 14A-14G or FIG. 16, so as to define a configurationsimilar to that depicted in FIGS. 5-6 at region 28 a.

Furthermore, inflation lumen 24 c and/or guidewire lumen 30 c can beconfigured to have any of a variety of cross-sectional shapes. Forexample and not limitation, the cross-sectional shape inflation lumen 24c can be substantially elliptical, substantially rectangular, or bedefined by a polygon (e.g., a hexagon), among others.

In further accordance with a further aspect of the invention, and asnoted above, first guidewire tube 32, as illustrated in FIG. 7, can bearranged in a coaxial arrangement at least with a portion of inflatablemember 114. Thus, in accordance with a further aspect of the invention,catheter 100 can be configured to include a transition along at least aportion of its length. In particular, catheter 100 can have a firstsegment along its length in which second guidewire tube 30 is arrangedin a side-by-side configuration or a modified, side-by-sideconfiguration, and a second segment in which first guidewire tube 32 isarranged in a coaxial configuration. Accordingly, it is an aspect of thepresent invention to include a catheter 100 having a transition along atleast a portion of its length.

Further in accordance with another aspect of the invention, the secondguidewire lumen can be configured to be entirely in a coaxialrelationship with inflation lumen along the length therebetween theproximal guidewire port 30 a and the distal guidewire port 30 b, orentirely in a side-by-side relation therebetween, or a combination ofthe two. That is, a portion of the length of the distal tubular member24 can be formed of a dual lumen member, as described, with anadditional portion of the distal tubular member formed of an outertubular member and an inner tubular member in coaxial relationship, suchthat at least the inner tubular member is joined in fluid communicationwith one of the lumens of the dual lumen member.

In accordance with a further aspect of the invention, the catheter caninclude an elongate main body having one or more stiffening members. Theterm “stiffening member” can include a filament, strand, wire, coil,tubular member, or other member to increase the stiffness of a sectionof the catheter elongate main body. Preferably, however, the stiffeningmember is a wire member.

In a preferred embodiment, and in accordance with an additional aspectof the invention, the catheter includes an elongate main body and aplurality of stiffening members disposed along a length of the elongatemain body. The plurality of stiffening members includes a firststiffening member and a second stiffening member disposed in anoverlapping and spaced relationship. Particularly, and as embodiedherein and schematically depicted in FIG. 1, catheter 100 can includefirst, second, and third stiffening members, 40, 42, and 44,respectively.

First stiffening member 40 has a proximal end 40 a, a distal end 40 b,and a midpoint therebetween. The midpoint is preferably equidistant fromthe proximal end and the distal end of the stiffening member. In oneembodiment, as shown in FIG. 1, first stiffening member 40 is disposedalong the proximal portion 102 of the elongate main body and has aproximal end secured to adapter 110 and a length sufficient extenddistally through and beyond lumen 20 c of proximal tubular member 20.The distal end of first stiffening member is freely floating orunattached to the catheter main body.

First stiffening member 40 can be secured to the adapter by adhesive,welding, or alternatively, can be embedded into the adapter during aninjection molding process. Alternatively, and as schematically depictedin FIG. 2, first stiffening member 40 can be secured to the elongatemain catheter body of catheter 100 such that at least a proximal portionof the stiffening member 40 is freely-floating or unsecured within theproximal tubular member 20. For example and not limitation, andintermediate location, such as the midpoint, or the distal end of firststiffening member 40 can be secured to intermediate tubular member 22 oranother member of the main body. In yet another alternative, firststiffening member 40 can have at least one of the proximal end or distalend secured to its proximal tubular member 20. For example and notlimitation, if the proximal tubular member is formed of metal, firststiffening member 40 can be welded, brazed, or soldered at or near thedistal end of proximal tubular member 20 or to a region proximal to thedistal end of proximal tubular member 20.

First stiffening member 40 can include a taper or stepped region ofincreasing or decreasing cross dimension. For example and notlimitation, FIG. 1 demonstrates that first stiffening member isconfigured to have a stepped region of increasing cross dimension withthe transition located within the proximal tubular member 20. Asdepicted, the stepped region of increasing cross dimension can bedefined by an extension member 60 secured to the distal region 40 b ofthe first stiffening member. However, first stiffening member 40 can beconfigured to include a taper, if desired, which extends along a portionof the entire length of the member, as depicted in FIG. 18E and FIG. 28.Additionally, first stiffening member can be configured to have auniform cross section which changes from a circular configuration to asemi-circular configuration, as depicted in FIG. 28.

First stiffening member can have a length of approximately 110 to about125 cm and include a first section having an outer diameter of about 0.1mm, a second section having an outer diameter of 0.2 mm, and a thirdsection having an outer diameter of about 0.3 mm. However, it should berecognized that other lengths and dimensions can be used. In a preferredembodiment, the first stiffening member has a length disposed in theproximal tubular lumen 20 c such that the transition from a larger outerdiameter to a smaller outer diameter is proximal to the distal endregion 20 b of proximal tubular member 20.

FIG. 1 further depicts second stiffening member 42 having a proximal end42 a and a distal end 42 b and a length therebetween. Second stiffeningmember 42 can be secured to at least one region of the elongate mainbody of catheter 100. Alternatively, and as depicted in FIG. 18B, eachof first and second stiffening member can be secured to a support member92 disposed along the elongate main body.

As yet another alternative, catheter 100 can include an engagementmember 41 to define a longitudinal cavity or space between theengagement member 41 and the inner surface of the elongate main body toengage the stiffening member in the longitudinal cavity or space, asdepicted in FIG. 18H.

For example, and not limitation, second stiffening member 42 can bedisposed in inflation lumen 22 c and secured at an intermediate locationto an inner surface of intermediate tubular member 22. In this regard,the distal end 42 b and the proximal end 42 a of second stiffeningmember 42 can each be configured to freely-float within the lumen 22 c.As another illustrative example, second stiffening member 42 can besecured at least one of its proximal end or its distal end to a regionof the elongate main body of catheter 100. Preferably, and asillustrated in FIG. 1, second stiffening member 42 is secured withinreinforcement member 26. Reinforcement member 26 is preferably apolymeric member including but not limited to a tubular member or afiller material. The added material 26 can fuse into the sidewall of theelongate main body when heated or melted and prevent the stiffeningmember from disrupting the sidewall of the catheter.

Preferably, as embodied herein and depicted in FIG. 1, second stiffeningmember 42 is in an overlapping configuration with a portion of firststiffening member 40. That is, the distal end 40 b of first stiffeningmember 40 preferably extends distally beyond the proximal end 42 a ofsecond stiffening member 42. More preferably, the stiffening members arein non-connected relationship. As illustrated in FIG. 18E, firststiffening member 40 can be configured to include a distal taper andsecond stiffening member can be configured to include a proximal taper.Further, the overlapping configuration can include the distal taperedarea of the first stiffening member located along a length correspondingto the proximal tapered area of the second stiffening member.

Catheter 100 can include a third stiffening member 44, as illustrated inFIG. 1. Third stiffening member 44 has a body including a proximal end44 a, a distal end 44 b, and a length therebetween. As demonstrated inFIG. 1, can best be viewed in FIGS. 4A, 4B, and 4C, third stiffeningmember 44 can be configured in an overlapping configuration with aportion of second stiffening member 42 and can extend distally to aregion near or into inflatable member 114.

Third stiffening member 44 can be secured to at least one region of theelongate main body of catheter 100. For example, and not limitation,third stiffening member 44 can be disposed in inflation lumen 24 c andsecured at an intermediate location to an inner surface of distaltubular member 24. In this regard, the distal end 44 b and the proximalend 44 a of third stiffening member 44 can be secured at least one ofits proximal end or its distal end to a region of the elongate main bodyof catheter 100. Preferably, and as illustrated in FIG. 1, thirdstiffening member 44 is secured within filler material or reinforcementmember 28.

As embodied herein and depicted in FIG. 27A to 27 AJ, the plurality ofstiffening members can include at least first and second stiffeningmembers arranged in a variety of ways along the elongate main body. Inthis manner and as illustrated in FIG. 27A to 27AJ, any of the first,second, or third stiffening members can include a distal taper, aproximal taper, or both a distal and proximal taper, depending upon theintended function and performance of the catheter. Additionally, any ofthe first, second, or third stiffening members can be configured withouta taper. For example, embodiment number 1 of FIG. 27A depicts a firststiffening member having a tapered distal end and a second stiffeningmember having a tapered distal end, wherein the first and secondstiffening members are in a non-overlapping arrangement. Embodiment 2 ofFIG. 27B depicts a first stiffening member having a tapered distal end,a second stiffening member of uniform diameter and a third stiffeningmember having a tapered distal end. The remaining embodiments areevident from the drawings.

In yet another embodiment of the invention, the catheter can beconfigured to achieve a varied flexibility along a length thereof byincluding a tubular member having at least one stiffening membercircumferentially disposed about the outer surface of the tubularmember. As embodied herein and schematically depicted in FIGS. 30A and30B, catheter 100′ includes tubular member 30′ comprising at least onestiffening member 40′ including at least one cluster 46 including aplurality of helical turns or rotations 46 a circumferentially disposedabout the outer surface of tubular member 30′ along a length of cluster46.

The plurality of helical turns have a predetermined pitch P. In thismanner, the plurality of helical turns 46 a can be configured to have aconstant pitch along a length of the individual cluster 46, as shown inFIGS. 30A and 30B. Alternatively, the plurality of helical turns 46 acan be configured to have a varied pitch along the length of theindividual cluster (not shown).

In one embodiment, the at least one stiffening member includes aplurality of clusters 46 disposed along the length of the tubularmember. The plurality of clusters can be configured to vary axialflexibility along a length of the tubular member. In this regard, theplurality of clusters includes a first cluster having a firstflexibility disposed along a first length of the tubular member and asecond cluster having a second flexibility disposed along a secondlength of the tubular member. The second flexibility can be greater thanthe first flexibility.

The variation in flexibility along the length of the tubular member canbe achieved in many ways. For example and not limitation, the firstcluster can be formed from a first material and the second cluster canbe formed from a second material, the second material having greaterflexibility than the first material. Accordingly, the length of thetubular member that is associated with the second cluster has a greaterflexibility than the length of the tubular member associated with thefirst cluster. In this regard, the second cluster can be disposed alonga distal portion of the tubular member and the first cluster can bedisposed along the proximal portion of the tubular member. Accordingly,a tubular member having an increased flexibility distally along thelength of the tubular member is defined.

Alternatively, the first cluster can include a first plurality ofhelical turns having a first pitch and the second cluster can include asecond plurality of helical turns having a second pitch. The first pitchcan be configured to be different than the second pitch. In this manner,the second pitch can be configured to have a longer pitch than the firstpitch to define a cluster having greater flexibility along its length.The first cluster can be disposed along a length of the tubular memberat which a greater stiffness is desired.

For the purpose of illustration, and as schematically depicted in FIG.30B, tubular member 30′ is configured to include proximal section 102′,distal section 106′ and intermediate section 104′ disposed therebetween.In preferred embodiment, proximal section 102′ includes a first cluster46 including a first plurality of helical turns 46 a having a firstpitch P1 along the length of the first cluster, intermediate section104′ includes a second cluster 46 comprising a second plurality ofhelical turns 46 a having a second pitch P2 along a length thereof, anddistal section 106′ includes a third cluster including a third pluralityof helical turns 46 a having a third pitch P3. As depicted, the firstplurality of helical turns has the shortest pitch P1 and the thirdplurality of helical turns has the longest pitch. Further, the secondplurality of helical turns has a second pitch P2 that is shorter than P3but longer than P1. Accordingly, the first, second, and third pluralityof helical turns and respective clusters are configured to define atubular member having an increased flexibility distally along itslength. To this end, a section of the tubular member having greaterstiffness can be achieved by including a cluster comprising a pluralityof helical turns having a shorter pitch along a length thereof and asection of the tubular member having greater flexibility can be achievedby including a cluster comprising a plurality of helical turns having alonger along a length thereof. Accordingly, a tubular member havingvariable stiffness or flexibility can be achieved by fluctuating thepitch of the plurality of helical turns between the plurality ofclusters. Alternatively, the cluster can be configured to include aplurality of helical turns in which each successive helical turn has anincreasing length in pitch.

In one embodiment, as depicted FIGS. 30A and 30B, the at least onestiffening member can include multiple stiffening members in which eachcluster of the plurality of clusters is associated with an adjacentcluster by an interconnnector 48. The interconnector 48 can be linear asdepicted in FIG. 30A or non-linear as depicted in FIG. 30B. For exampleand not limitation, interconnector 48 can have a longitudinal, wavysinusoidal configuration, or any other configuration as would beappreciated in the art. Alternatively, the least one stiffening membercan comprise a unitary stiffening member configured to include at leastone cluster including a plurality of helical turns.

In a further aspect of the invention, and as depicted in FIGS. 31 A and31 B, a coating 80′ can be applied on the surface of tubular member 30′having at least one stiffening member including a cluster of helicalturns 46 to provide a tubular member having a smooth, continuous outersurface. In this manner, a polymeric, e.g., nylon, coating can beextruded or pultruded over the tubular member 30′ and clusters ofhelical turns 46. However, a variety of other techniques for applyingthe coating can be utilized. For example and not limitation, the coatingcan be applied by techniques including powder coatings, spray coating,and dip coating, as understood in the art.

During the coating process, the thickness of the coating and thecross-sectional area of the tubular member can be varied, if desired, asfor example by bump extrusion techniques during which vacuum pressureduring the extrusion process is varied to define a varied degree ofthickness or cross-sectional area along the wall of the tubular member.Accordingly, the varied thickness or varied cross-sectional area of thetubular member further defines a tubular member having variablestiffness along a length thereof.

In addition to or in lieu of coating 80′, shrink wrap 80 can be appliedover the tubular member and cluster of coil members, as depicted in FIG.30A. For example and not limitation, the shrink wrap tubing 80′ can be apolymer material such as PET. Moreover, the tubular member can furtherinclude a base polymeric layer disposed on the outer surface of thetubular member and under the at least one stiffening member, if desired.

At least one stiffening member can be formed from a metallic ornon-metallic element. For example and not limitation, the stiffeningmember can be formed from a metal such as stainless steel. If desired, anon-metallic member can be used. For example, aramid, boron, glassfiber, carbon fiber, PEEK fibers and blends thereof. The non-metallicstiffening member can be woven, spun, braided, or coiled onto thetubular member. Further, the non-metallic stiffening member can be usedwhen MRI compatibility is desired. For the purpose of illustration andnot limitation, the tubular member having varied flexibility can beutilized as an outer or inner tubular shaft member of a catheter systemor alternatively as a shaft section of a catheter system.

As embodied herein and depicted in FIGS. 1 and 7, and further inaccordance with another aspect of the invention, catheter 100 includesat least one radiopaque marker band 36 affixed to a surface of firstguidewire tube 32. As depicted in FIG. 7, marker band 36 includes akeyway in which the distal end region of third stiffening member 44 isslidingly disposed. Accordingly, third stiffening member 44 is slidinglyengaged within marker band 36 to facilitate flexing, and can extenddistal to marker band 36. Preferably, third stiffening member 44 furtherincludes a stopper 50 or protrusion to increase pushability of catheter100. Alternatively, the third stiffening member 44 can also terminate atthe proximal end of inflatable member 114.

In an alternative embodiment, as schematically depicted in FIG. 2,catheter 100 can include only a first stiffening member 40 and a secondstiffening member 42. As shown in FIG. 2, second stiffening member 42extends proximally from marker band 36 to first stiffening member 40 andis in an overlapping configuration with a portion of first stiffeningmember 40. In an alternative embodiment, second stiffening member can bedisposed distal of first stiffening member 40 and have a distal endregion 42 b terminate proximal to inflatable member 114. In this manner,second stiffening member 42 can be secured to the elongate main body ofthe catheter, for example by reinforcement member 26, 28. Alternatively,a single stiffening member can be provided. The single stiffening membercan extend distally from proximal tubular member 20 to a desiredlocation along the length of the main body. The single stiffening membercan be secured at its proximal end or, more preferably, at anintermediate or distal location along its length.

In accordance with another embodiment of the invention, and as depictedin FIG. 22, the plurality of stiffening members includes a secondstiffening member disposed distal of the first stiffening member suchthat a gap is defined between the first stiffening member and the secondstiffening member. Further, a support member can be disposed between thefirst and second stiffening members, as shown in FIGS. 22 and 24.Alternatively, and as depicted in FIG. 29, the support member can bedisposed in the distal section of the catheter. In one embodiment, thesupport member is in association with the inflatable member. The supportmember can be a tubular member, such as a polymeric or non-polymerictube, a coil member or the like. In one embodiment, the support memberis a carbon or carbon reinforced tubular member. Preferably, the carbonor carbon reinforced member is articulated.

In accordance with a further aspect of the invention, the plurality ofstiffening members is configured to vary the axial flexibility along alength of the elongate main body of catheter 100. The plurality ofstiffening members can be configured in a variety of ways to vary theaxial flexibility along a length of the elongate main body. For exampleand not limitation, the material used to form each stiffening member candefine the desired stiffness for each portion of the catheter body. Inthis manner, a variety of materials can be used for any of the pluralityof stiffening members. For example and not limitation, the stiffeningmember can be formed of metals or metal alloys, such as stainless steel,nitinol, titanium, tantalum, Eligiloy, cobalt, chrome, nickel and anycombination or alloy thereof. Alternatively, the stiffening members canbe made of polymeric materials, such as polyamide, including polyamidecopolymers, and polyimides, reinforced resin materials, including carbonfiber reinforced material, glass fiber reinforced material, and boronfiber reinforced material. As yet another alternative, the stiffeningmember can be formed of synthetic materials, such as carbon, Dacron®and/or Kevlar®, available from E.I. du Pont de Nemours and Company.

Each stiffening member can be formed of a different material or amaterial having a different stiffness to vary the flexibility along alength of the elongate main body of catheter 100. Alternatively, atleast two stiffening members can be formed of the same material ormaterials having similar stiffness to define a length of the elongatemain body having uniform stiffness. For the purpose of illustration andnot limitation, first stiffening member can be formed of stainless steel40, second stiffening member 42 can be formed of a carbon material orcarbon reinforced material, and third stiffening member 44 can be formedof nitinol. In this regard, the region of the elongate main bodycorresponding to the nitinol stiffening member can have a greater axialflexibility that the areas corresponding to the stainless steel orcarbon stiffening members. Accordingly, one variety of varying theflexibility along a length of the catheter includes the selection ofmaterial used to form each of the plurality of stiffening members.

Moreover, the stiffening member can be configured to have a variedflexibility along its length. For example, the stiffening member can beconfigured to include an increased cross dimensional area to reduceaxial flexibility along its length, as depicted in FIG. 1, or caninclude a portion having a circular cross section and a portionincluding a semi-circular cross section as shown in FIG. 28, or can beotherwise changed in cross section, such as flattened, to changestiffness.

Alternatively, the stiffening member can be configured to include atleast one cut 88 along its length. Preferably, the at least one cutincludes a plurality of cuts along the length of the stiffening member.As embodied herein and depicted in FIGS. 19A and 19B, the at least onecut 88 can be a circumferential cut defining a circumferential groove90. In this manner, the spacing between adjacent grooves can be variedalong the length of the stiffening member to define an increasing ordecreasing variation in flexibility along the length of the stiffeningmember. The flexibility of the stiffening member having at least one cutalong its length can further be increased or decreased by tapering theouter diameter of the stiffening member, as shown in FIG. 19A.

As yet another alternative, the cut 88 along the length of thestiffening member can include at least one longitudinal cut along itslength, as depicted in FIG. 25. In this manner, the at least onelongitudinal cut can include a plurality of longitudinal cuts in whichat least a first longitudinal cut has a length different than a secondlongitudinal cut, as illustrated in FIG. 26, to vary the stiffness ofthe stiffening member.

Additionally, the length of each stiffening member will be dependent onthe total number of stiffening members. For example and not limitation,if catheter 100 has three stiffening members, first stiffening member 40can generally have a length of approximately 110 to 125 cm. Preferably,first stiffening member 40, as illustrated in FIGS. 1 and 2, terminatesproximal to guidewire port 30 a. Second stiffening member 42 generallyhas a length of about 5 to 15 cm. As depicted in FIG. 1, secondstiffening member 42 preferably extends across guidewire port 30 a.Third stiffening member 44 generally has a length of approximately 5 to30 cm and preferably, greater than 10 cm. Preferably, third stiffeningmember extends proximally across gap 24 d. If only first stiffeningmember 40 and second stiffening member 42 are used, at least onestiffening member would have a greater length.

As illustrated in FIGS. 18A to 18G at least one of the plurality ofstiffening members can include a linear or, alternatively, an non-linearconfiguration. For example and not limitation, the first stiffeningmember can have a wavy configuration and the second stiffening membercan have a linear configuration, as depicted in FIG. 18A. Alternatively,each of the first and second stiffening members can have a linearconfiguration as depicted in FIG. 18B and FIG. 18C. Alternatively, atleast one stiffening member can be configured to include a linearportion and a non-linear portion as illustrated in FIGS. 18D and 18G.The non-linear configuration can include but not limited to a wavyconfiguration FIG. 18F or a helical configuration FIG. 18D.

Depending upon the materials of construction, and the intended use ofthe catheter, it can be beneficial to further reinforce the ports alongthe length of the catheter 100. Hence, in further accordance with theinvention, and as schematically depicted in FIG. 1, catheter 100 canfurther include a first reinforcement member 26 and a secondreinforcement member 28 disposed adjacent to proximal guidewire port 30a and gap 24 d, respectively.

For the purpose of illustration and not limitation, first reinforcementmember 26 is disposed in lumen 22 c adjacent to proximal guidewire port30 a and defines reinforcement region 26 a. Additionally, secondreinforcement member 28 is disposed in inflation lumen 24 c adjacent todistal guidewire port 24 d, and defines reinforcement region 28 a, asdemonstrated in FIGS. 1 and 2. Each reinforcement member is melted uponformation of the corresponding joint, as previously described.

At least one of the first or second reinforcement members 26,28 can bein the form of a polymeric member formed of materials such as forexample and not limitation, polyamide, PEEK, polyether ketone,polyketone. Preferably, at least one of first and second reinforcementmembers is a nylon tubular member.

As mentioned, first reinforcement member 26 and second reinforcementmember 28 form first reinforcement region 26 a and second reinforcementregion 28 a, respectively. For the purpose of illustration, a mandrelmade of non-stick material, such as PTFE, and preferably having adesired shape corresponding to a lumen is slid within the lumen of thetubular reinforcement member. Additionally, if desired, a correspondingstiffening member can also be inserted in the lumen of the tubularreinforcement member. For example, second stiffening member 42 can bedisposed in the reinforcement member 26, and third stiffening member 44can be inserted in the lumen of second tubular reinforcement member 28.A shrink tube can be placed over the welding zone and the assembly isthen heated. The application of heat will act to melt the polymermaterial, and cause the molten polymer of the first tubularreinforcement member 26 to form a first reinforcing region 26 a, andcause the molten polymer of the second tubular reinforcement member 28to form second reinforcing region 28 a.

As illustrated in FIG. 3, after fusing or melting first reinforcementmember 26, for example by applying heat, the mandrel is removed, andinflation lumen 24 c is defined (by the mandrel), and the molten polymerwhich corresponds to first reinforcement region 26 a causes secondstiffening member 42 to become embedded within reinforcing region 26 a.Similarly, as depicted in FIG. 6, inflation lumen 24 c is defined and aportion of third stiffening member 44 is embedded within reinforcementregion 28 a, which is defined by the molten polymer of secondreinforcement member 28. Advantageously, each of reinforcement region 26a and 28 a can act to reinforce or support a length of elongate mainbody of catheter 100, and also to secure stiffening member 42 andstiffening member 44, respectively. Further, the reinforcement regioncan act to seal the inflation lumen at the guidewire ports.

In further accordance with the invention, a sheath is provided for aballoon catheter. In one embodiment, the balloon catheter is a rapidexchange catheter having a proximal port in the sidewall of the catheterbody. As shown and depicted in FIGS. 35A and 35B sheath 200 preferablyincludes a proximal section 202 and a distal section 204. In onepreferred embodiment, the proximal sheath section 202 is stationary andis configured to cover the proximal port disposed in the sidewall of therapid exchange catheter and the distal sheath section 204 is retractableand is configured to cover at least a balloon portion of the catheter,which may include a stent.

For the purpose of illustration and not limitation, in one embodiment,the proximal sheath section 202 extends from the proximal section of thecatheter body to a point between the proximal side port and the balloon.In operation, the distal sheath section 204 is retracted proximally andtelescopically slides over a surface of the proximal sheath section 202to expose the balloon (and stent if provided). In this manner, thedistal sheath section 204 can be operatively attached to the pull wireor actuator (FIG. 34, 220), for example, with a radiopaque pull collar.

For the purpose of illustration and not limitation, and as depicted inFIGS. 33 and 34, the actuator, e.g., pull wire 220, can be disposed inthe lumen of the proximal section of the catheter body 300. For example,the pull wire 220 can be disposed in a dedicated lumen 320 disposedwithin the lumen of the inflation shaft 340 of the catheter 300, asdepicted in FIG. 34. Alternatively, as depicted in FIG. 33, the actuator220 can be disposed within a polymeric microtube 240 that is secured tothe inner surface of the lumen of the inflation shaft 340 of catheter300. Further, the microtube 240 can be free floating in the lumen of theinflation shaft 340, i.e., not secured to the lumen. In any arrangement,the pull wire extends coaxially along the lumen of the catheter. In apreferred embodiment, the actuator 220 exits the lumen of the catheterat a point distal of proximal tubular member and extends distally alongthe exterior and outer surface of the catheter body, as depicted inFIGS. 33 and 34. The proximal sheath section 202 is disposed on thecatheter body such that the sheath covers at least a portion of theproximal section of the catheter, the proximal port in the sidewall ofthe catheter body and at least a portion of the actuator along theexterior of the catheter body (not shown). Accordingly, the sheath canbe configured such that a stationary sheath section provides aprotective cover for the proximal side port of the catheter and theactuator while further allows uncompromised movement of the actuator.The proximal sheath section 202, preferably, is secured to the catheterbody at or near the proximal port to ensure lack of movement of thesheath section. Additionally, the retractable distal sheath section 204provides a protective cover for the balloon section of the catheterbody.

As depicted in FIG. 36A and 36B, the sheath can be configured to furtherinclude a bellowed section 206 disposed between the proximal sheathsection 202 and the distal sheath section 204. In this manner, thesheath can be formed from a unitary tubular member or alternatively canbe made from multiple tubular members secured together, for example, bywelding or adhesively bonding the proximal sheath section 202, bellowedsheath section 206 and the distal sheath section 204. The compressiblebellowed section 206 provides variable sheath length. In this manner,the bellowed section is operatively attached to a pull wire or actuator.During retraction, the bellowed section compresses and causes the distalsheath section to move proximally thereby exposing the stent and theballoon.

A variety of types of medical devices are suitable for delivery by thecatheter of the present invention. For purpose of example and notlimitation, a medical device can be provided, for example, in the formof a balloon-expandable stent (not shown). Such devices are generallywell known in the art. However, the catheter of the present invention isnot limited to the delivery of balloon expandable stents. Other devicesmay also be used. For example, stentgrafts, bifurcation systems, coils,filters, heart valve repair devices, and embolic protection devices maybe delivered within a patient's vasculature using catheter 100 of thepresent invention. Other devices such as a prosthesis retrievalmechanism, antennae for intravascular MRI, or visual or ultrasonicimaging devices can also be delivered or used with catheter at apredetermined location in a patient's luminal systems. Moreover,combinations of medical devices and/or beneficial agents orpharmaceutically active agents can also be delivered using the device ofthe present invention. For example, multiple stents or a combination ofstents and embolic protection devices and/or beneficial agents can bedelivered using catheter of the present invention, mounted on separateinflatable members (not shown). Further, the catheter of the inventionmay include two or more balloons or one balloon with a plurality ofinflatable sections. Accordingly, in the event that a catheter isrequired with more than one inflation lumen, for example for theintroduction of contrast media or inflation of a second balloon, theproximal section of elongate main body can further include a secondproximal tubular member coaxially disposed about proximal tubular member30 or hypotube. Preferably, the second proximal member is a polymericmaterial, e.g., nylon or HDPE, however, the second proximal member maybe formed of a hypotube.

Although reference has been made to a catheter having an inflatablemember 114 at its distal body section, a variety of other structures fordelivering to or use within a luminal system can be provided. Forexample, if desired, it is also possible to deliver self-expandingmedical devices on a catheter of the invention. In accordance with thisaspect of the invention, a medical device in the form of aself-expanding prosthesis, such as a self-expanding stent, can beprovided. If a self-expanding medical device is to be delivered usingthe catheter of the invention, it may be necessary to provide arestraint device to restrain expansion of the medical device, and permitdeployment at the appropriate time by a physician. Such a restraintdevice can take the form of a retractable sheath having a proximal end,a distal end, an inner surface and an outer surface. Sheath can bewithdrawn proximally so as to deploy the medical device by actuating anactuator (not shown). The actuator can be a simple push-pull actuator, agear mechanism, or a hydraulic actuator, spring loaded actuator, orpneumatic actuator. Alternatively, the actuator can be electrically orchemically driven artificial muscle, which is based on contractilealloys or polymers. For example and not limitation, the contractilealloys can be Flexinol, available from Dynalloy Inc. Costa Mesa, Calif.,or polyacrylonitrile-polypyrrole- or polyvinylalcohol- fibers.

The actuator can be attached to sheath directly at proximal end ofsheath, or may be attached by a pull wire. Alternatively, the actuatorcan be attached to a unravel- able system, such as a knitted member.Such actuators are provided in, for example, U.S. Pat. No. 6,425,898 toWilson, U.S. Pat. No. 5,906,619 to Olson, U.S. Pat. No. 5,772,669 toVrba and U.S. Pat. No. 6,527,789 to Lau et al., each of which isincorporated by reference herein in its entirety.

A variety of other restraint devices can additionally or alternativelybe used. For example, restraint bands (not shown) could alternatively beused that are retracted proximally by a pull wire attached to anactuator. Similarly, restraint device can take the form of a frangibleenvelope (not shown) with a pull wire embedded within the wall of theenvelope. Self expanding medical device can accordingly be deployed byactuating actuator, which pulls back on the pull wire, splitting openthe frangible envelope, resulting in deployment of the self-expandingdevice. Other possible actuators (e.g., thermal actuation, wirerestraints, balloon-ruptured restraints and the like) are also possibleand within the scope of the invention.

In accordance with another aspect of the invention and as previouslydescribed in conjunction with certain aspects of the invention, a methodof performing a medical procedure is provided. The method includesproviding a catheter as described herein, disposing a guidewire within alumen of a patient, and inserting the guidewire through at least one ofthe first guidewire lumen and the second guidewire lumen of thecatheter.

The method in accordance with the invention can also include providingand inflating an inflatable member in a lumen of a patient, retractingthe guidewire until a distal extremity of the guidewire is proximal tothe proximal guidewire port 30a of the intermediate section 104 of thecatheter, and allowing blood to perfuse through the first guidewirelumen of the distal body portion.

The methods and systems of the present invention, as described above andshown in the drawings, provide for a catheter with superior propertiesincluding superior flexibility and pushability. It will be apparent tothose skilled in the art that various modifications and variations canbe made in the device and method of the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention include modifications and variationsthat are within the scope of the appended claims and their equivalents.

1. A catheter comprising: an elongate main body including at least aproximal section having a proximal end, a distal end and a lumen definedtherethrough and a distal section having a proximal end, a distal endand a lumen defined therethrough; a guidewire tube defining a guidewirelumen therethrough extending through at least a portion of the distalsection of the elongate main body; the proximal section including ahypotube; the distal section including an inflatable member; and aplurality of stiffening members including at least a first stiffeningmember and a second stiffening member disposed along a length of theelongate main body, each of the plurality of stiffening members having aproximal end, a distal end, and a length therebetween, wherein the firststiffening member is in a longitudinally overlapping and transverselyspaced relationship with the second stiffening member.
 2. The catheterof claim 1, wherein the second stiffening member is disposed distal ofthe first stiffening member such that a gap is defined between the firstand second stiffening members.
 3. The catheter of claim 1, wherein thefirst stiffening member is a carbon tubular member.
 4. The catheter ofclaim 1, wherein a support member is disposed between the firststiffening member and the second stiffening member.
 5. The catheter ofclaim 4, wherein each of the distal end of the first stiffening memberand the proximal end of the second stiffening member is secured to thesupport member.
 6. The catheter of claim 4, wherein the support memberis formed from polymeric material.
 7. The catheter of claim 1, whereinthe catheter further includes a carbon tube disposed between the firstand second stiffening members.
 8. The catheter of claim 7, wherein thecarbon tube is articulated.
 9. The catheter of claim 1, wherein at leastone of the plurality of stiffening members is secured to an innersurface of the elongate main body.
 10. The catheter of claim 1, whereinthe at least one of the plurality of stiffening members is secured tothe inner surface by filler material.
 11. The catheter of claim 1,wherein the catheter further includes an engagement member secured to aninner surface of the elongate main body such that a space is definedbetween the engagement member and the inner surface of the elongate mainbody.
 12. The catheter of claim 11, wherein at least one of theplurality of stiffening members has a length disposed in the spacedefined between the engagement member and the inner surface of theelongate main body.
 13. The catheter of claim 1, wherein the distal endof at least one of the plurality of stiffening members has a lengthextending within the inflatable member.
 14. The catheter of claim 1,wherein the guidewire tube extends within the inflatable member, atleast one marker band disposed circumferentially around an outer surfaceof the guidewire tube, the marker band having an inner surface.
 15. Thecatheter of claim 14, wherein at least a portion of at least one of theplurality of stiffening members is disposed between the outer surface ofthe guidewire tube and the inner surface of the at least one markerband.
 16. The catheter of claim 15, wherein the portion of the at leastone of the plurality of stiffening members is slidingly received betweenthe outer surface of the guidewire tube and the inner surface of themarker band.
 17. The catheter of claim 15, wherein at least one of theplurality of stiffening members further includes a protrusion disposedalong the length thereof, wherein the protrusion is disposed proximatethe distal end of the at least one of the plurality of stiffeningmembers for butting engagement with the marker band.
 18. The catheter ofclaim 1, wherein the elongate main body further includes a thirdstiffening member disposed along a length of the elongate main body. 19.The catheter of claim 1, wherein the plurality of stiffening members isconfigured to vary the flexibility along the elongate main body of thecatheter.
 20. The catheter of claim 1, wherein the plurality ofstiffening members includes a first stiffening member formed from afirst material and a second stiffening member formed from a secondmaterial, the first material having a flexibility different than thesecond material.
 21. The catheter of claim 20, wherein at least one ofthe first material and the second material is metal, metal alloy,polymer, carbon, composite, and carbon reinforced material.
 22. Thecatheter of claim 1, further comprising a balloon, wherein the balloonis formed from a tubular member having at least one recess along aportion of a surface thereof.